In acoustics, noise measurement can be for the purpose of measuring environmental noise[1] or measuring noise in the workplace. Applications include monitoring of construction sites, aircraft noise, road traffic noise, entertainment venues and neighborhood noise. One of the definitions of noise covers all "unwanted sounds".[2] When sound levels reach a high enough intensity, the sound, whether it is wanted or unwanted, may be damaging to hearing.[3] Environmental noise monitoring is the measurement of noise in an outdoor environment caused by transport (e.g. motor vehicles, aircraft, and trains), industry (e.g. machines) and recreational activities (e.g. music). The laws and limits governing environmental noise monitoring differ from country to country.

At the very least, noise may be annoying or displeasing or may disrupt the activity or balance of human or animal life, increasing levels of aggression, hypertension and stress. In the extreme, excessive levels or periods of noise can have long-term negative health effects such as hearing loss,[4] tinnitus,[5] sleep disturbances,[6] a rise in blood pressure,[7] an increase in stress[8] and vasoconstriction,[9] and an increased incidence of coronary artery disease.[10][11] In animals, noise can increase the risk of death by altering predator or prey detection and avoidance, interfering with reproduction and navigation,[12] and contributing to permanent tinnitus and hearing loss.[13][14]

Various interventions are available to combat environmental noise. Roadway noise can be reduced by the use of noise barriers,[15] limitation of vehicle speeds,[16] alteration of roadway surface texture, limitation of heavy vehicles, use of traffic controls that smooth vehicle flow to reduce braking and acceleration, and tire design.[17] Aircraft noise can be reduced by using quieter jet engines,[18][19][20] altering flight paths and considering the time of day to benefit residents near airports.[21] Industrial noise is addressed by redesign of industrial equipment, shock mounted assemblies and physical barriers in the workplace.[22]

Noise may be measured using a sound level meter at the source of the noise.[23][24][25] Alternatively, an organization or company may measure a person's exposure to environmental noise in a workplace via a noise dosimeter.[26] The measurements taken using either of these methods will be evaluated according to the standards below.

## Contents

* 1 Audio Systems and Broadcasting
* 2 Standards
* 3 See also
* 4 References
* 5 External links

## Audio Systems and Broadcasting[edit]

Noise measurement can also be part of a test procedure using white noise, or some other specialized form of test signal. In audio systems and broadcasting, specific methods are used to obtain subjectively valid results in order that different devices and signal paths may be compared regardless of the inconsistent spectral distribution and temporal properties of the noise that they generate. In particular, the ITU-R 468 noise weighting was devised specifically for this purpose and is widely used for professional audio and broadcast measurements.

## Standards[edit]

There are a number of standards for noise measurement, each with a different goal or focus, including:

* Standard:ITU-R BS 468 widely used in Broadcasting and professional Audio.
* Standard:IEC A-weighting is widely used in Environmental Noise measurement.
* Standard:CCIR recommendation 468-4 is now maintained as ITU-R BS 468
* Standard:CCITT 0.41 refers to 'Psophometric weighting' used on telephone circuits.
* Standard:CCITT P53 is now continued as CCITT0.41
* Standard:BS 6402:1983 specifies Personal sound exposure meters.
* Standard:BS 3539:1968 specifies Sound level meters for motor vehicle noise.
* Standard:BSEN 60651 supersedes BS 5969:1981 Sound level meters

## See also[edit]

* Sound power level LWA
* Audio system measurements
* Rumble measurement
* Noise (environmental)
* Noise pollution
* Noise music
* Noise dosimeter
* Equal-loudness contour
* A-weighting
* C-weighting
* Weighting filter

## References[edit]

1. ^ Audio, NTi. "Unattended Noise Monitoring" (PDF). www.nti-audio.com.
2. ^ Goines, Lisa; Hagler, Louis (March 2007). "Noise Pollution: A Modern Plague". Southern Medical Journal. 100 (3): 287–294. CiteSeerX 10.1.1.504.8717. doi:10.1097/smj.0b013e3180318be5. ISSN 0038-4348. PMID 17396733. S2CID 23675085.
3. ^ "CAOHC Noise Measurement Course". www.caohc.org. Retrieved 2020-11-21.
4. ^ "Safety and Health Topics | Occupational Noise Exposure | Occupational Safety and Health Administration". www.osha.gov. Retrieved 2020-10-10.
5. ^ "Causes". www.ata.org. 2015-03-02. Retrieved 2020-10-10.
6. ^ Halperin, Demian (2014-12-01). "Environmental noise and sleep disturbances: A threat to health?". Sleep Science. 7 (4): 209–212. doi:10.1016/j.slsci.2014.11.003. ISSN 1984-0063. PMC 4608916. PMID 26483931. S2CID 16121980.
7. ^ Chang, Ta-Yuan; Hwang, Bing-Fang; Liu, Chiu-Shong; Chen, Ren-Yin; Wang, Ven-Shing; Bao, Bo-Ying; Lai, Jim-Shoung (2013-04-15). "Occupational Noise Exposure and Incident Hypertension in Men: A Prospective Cohort Study". American Journal of Epidemiology. 177 (8): 818–825. doi:10.1093/aje/kws300. ISSN 0002-9262. PMID 23470795.
8. ^ "Open Office Noise Increases Stress". WebMD. Retrieved 2020-11-21.
9. ^ "Open Office Noise Increases Stress". WebMD. Retrieved 2020-11-21.
10. ^ Hansell, Anna L.; Blangiardo, Marta; Fortunato, Lea; Floud, Sarah; Hoogh, Kees de; Fecht, Daniela; Ghosh, Rebecca E.; Laszlo, Helga E.; Pearson, Clare; Beale, Linda; Beevers, Sean (2013-10-08). "Aircraft noise and cardiovascular disease near Heathrow airport in London: small area study". BMJ. 347: f5432. doi:10.1136/bmj.f5432. ISSN 1756-1833. PMID 24103537. S2CID 2991257.
11. ^ Hammer Monica S.; Swinburn Tracy K.; Neitzel Richard L. (2014-02-01). "Environmental Noise Pollution in the United States: Developing an Effective Public Health Response". Environmental Health Perspectives. 122 (2): 115–119. doi:10.1289/ehp.1307272. PMC 3915267. PMID 24311120.
12. ^ "Review of noise impacts on marine mammals yields new policy recommendations". phys.org. Retrieved 2020-11-22.
13. ^ Salvi, Richard; Boettcher, Flint A. (2008), Conn, P. Michael (ed.), "Animal Models of Noise-Induced Hearing Loss", Sourcebook of Models for Biomedical Research, Totowa, NJ: Humana Press, pp. 289–301, doi:10.1007/978-1-59745-285-4_32, ISBN 978-1-59745-285-4, retrieved 2020-10-10
14. ^ Diaz, Rodney C. (2014). "Noise-induced hearing loss: perspectives". Current Opinion in Otolaryngology & Head and Neck Surgery. 22 (5): 373. doi:10.1097/MOO.0000000000000084. ISSN 1531-6998. PMID 25101939.
15. ^ Barrier, Hatko (2020-04-20). "How much does noise barrier cost?". Hatko Sound Barrier. Retrieved 2020-11-22.
16. ^ "NPC Resources: Noise Increases with Vehicle Speed". nonoise.org. Retrieved 2020-11-22.
17. ^ atlanticei (2019-03-20). "Reducing Excessive Noise Using Engineering Methods | Atlantic Environmental". Atlantic Environmental Incorporated. Retrieved 2020-11-21.
18. ^ "Leading the way in aircraft noise reduction | Engineering | University of Southampton". www.southampton.ac.uk. Retrieved 2020-11-21.
19. ^ Potter, Sean (2018-06-25). "NASA Technologies Significantly Reduce Aircraft Noise". NASA. Retrieved 2020-11-21.
20. ^ "Reducing Aviation Noise, Advancing the Aviation Enterprise | Volpe National Transportation Systems Center". www.volpe.dot.gov. Retrieved 2020-11-21.
21. ^ "How to Control Aircraft Noise? | Noise Pollution". Essays, Research Papers and Articles on Environmental Pollution. 2018-03-12. Retrieved 2020-11-21.
22. ^ "Controls for Noise Exposure | NIOSH | CDC". www.cdc.gov. 2020-06-22. Retrieved 2020-11-22.
23. ^ "How is Sound Measured?". It's a Noisy Planet. Protect Their Hearing. Retrieved 2020-11-22.
24. ^ "How decibel sound level meters work". Explain that Stuff. 2009-01-28. Retrieved 2020-11-22.
25. ^ "Sound-level meter | instrument". Encyclopedia Britannica. Retrieved 2020-11-22.
26. ^ Selwyn, Bob (September 1, 2010). "The Use of Noise Dosimeters in the Workplace -". Occupational Health & Safety. Retrieved 2020-11-22.

## External links[edit]

* Noise-Planet: app to make an open source noise map of environmental noise
* Koopen: Indoor Noise Measurement Dataset

* v
* t
* e

Noise (physics and telecommunications)

General|

* Acoustic quieting
* Distortion
* Noise cancellation
* Noise control
* Noise measurement
* Noise power
* Noise reduction
* Noise temperature
* Phase distortion

Noise in...|

* Audio
* Buildings
* Electronics
* Environment
* Government regulation
* Human health
* Images
* Radio
* Rooms
* Ships
* Sound masking
* Transportation
* Video

Class of noise|

* Additive white Gaussian noise (AWGN)
* Atmospheric noise
* Background noise
* Brownian noise
* Burst noise
* Cosmic noise
* Flicker noise
* Gaussian noise
* Grey noise
* Jitter
* Johnson–Nyquist noise (thermal noise)
* Pink noise
* Quantization error (or q. noise)
* Shot noise
* White noise
* Coherent noise
* Value noise
* Gradient noise
* Worley noise

Engineering
terms|

* Channel noise level
* Circuit noise level
* Effective input noise temperature
* Equivalent noise resistance
* Equivalent pulse code modulation noise
* Impulse noise (audio)
* Noise figure
* Noise floor
* Noise shaping
* Noise spectral density
* Noise, vibration, and harshness (NVH)
* Phase noise
* Pseudorandom noise
* Statistical noise

Ratios|

* Carrier-to-noise ratio (C/N)
* Carrier-to-receiver noise density (C/kT)
* dBrnC
* Eb/N0 (energy per bit to noise density)
* Es/N0 (energy per symbol to noise density)
* Modulation error ratio (MER)
* Signal, noise and distortion (SINAD)
* Signal-to-interference ratio (S/I)
* Signal-to-noise ratio (S/N, SNR)
* Signal-to-noise ratio (imaging)
* Signal-to-interference-plus-noise ratio (SINR)
* Signal-to-quantization-noise ratio (SQNR)
* Contrast-to-noise ratio (CNR)

Related topics|

* List of noise topics
* Acoustics
* Colors of noise
* Interference (communication)
* Noise generator
* Spectrum analyzer
* Thermal radiation

Denoise
methods|

| General|

* Low-pass filter
* Median filter
* Total variation denoising
* Wavelet denoising

|

2D (Image)|

* Gaussian blur
* Anisotropic diffusion
* Bilateral filter
* Non-local means
* Block-matching and 3D filtering (BM3D)
* Shrinkage Fields
* Denoising autoencoder (DAE)
* Deep Image Prior

Authority control: National libraries |

* Czech Republic

|

*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template